正激變壓器的設(shè)計
AP=4.3262cm4 Ae=194 mm2Aw=223mm2 Ve=19163mm3
AL=4690±25% Pt=433W (100KHz 25℃)
4、計算Np Ns.
(1).計算匝比n = Np /Ns 設(shè)Dmax= 0.4
n = Np / Ns = Vi / Vo = [Vin(min)×Dmax]/ (Vo+Vf)
Vf :二極管正向壓降取1V
Vin(min)=180×0.9×√2-20=209 VDC
Vin(max)=260×√2=370VDC
n=(209*0.4)/(13.8+0.7)=5.766取5.5
CHECK Dmax
Dmax=n(Vo+Vf)/Vin(min)= 5.5
(13.8+1)/209=0.3868≈0.387
Dmin=n(Vo+Vf)/Vin(max)= 5.5
(13.8+1) /370=0.218
(2).計算Np
Np=Vin(min)×ton/(ΔB×Ae)
Ton:MOS管導(dǎo)通時間 ton= Dmax/ fs=0.387/60×103=6.33uS
Np = (209×6.33)/( 0.20×194)=34.1取34TS
(3).計算Ns
Ns = Np / n = 34÷5.5=6.18取整為6 TS
(4). CHECK Np(以Ns驗算Np)
Np = Ns×n = 6×5 .5=33TS 取Np = 33TS
(5).確定NR
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